Water-tube steam-boiler.



No. 707,440. Patented Aug. I9, |902.

A. MEHLHURN.

WATER TUBE STEAM BOILEB.

(Application tiled Mar. 28, 1902.) (No Model.) 2 Sheets-Sheet 2.

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ALFRED MEI'ILIIORN, OF DIETRICHSDORF, GERMANY.

SPECIFICATION forming part of Letters Patent No. 707,440, dated August 19, 1902.

Application filed March 28, 190,2.

T0 @ZZ whom t may concern: l

Be it known that I, ALFRED MEHLHORN, a subject of the Emperor of Germany, residing at l1 Schwentiuestrasse, Dietrichsdorf, near Kiel, Germany, (whose post-oflice address is the same,) have invented certain new and useful Improvements in Tater-Tube Steam-Boilers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and use t-he same.

This invention relates to a water tube boiler by means of which an efEect approximate to that of a counter-current is obtained, and therewith intense development of heat and considerable utilization of the heatinggases.

In the accompanying drawings, Figure lis a transverse section of a boiler constructed according to this invention. Fig. 2 is a side elevation on a smaller scale,land Figs. 3 and 4t are sections of modified forms of boilers constructed on the same principle.

In the form shown in Fig. l the steam-boiler consists of the lower drum divided by a par-` tition into two parts a and e, the upper drum b f with the partition b and the lower drum t'. Both of the lower drums are connected with the upper drum by the nests of tubes I, II, and III, as well as by the down-pipes c d g h.

The compartments a et f, formed by the partitions in the drums, may be replaced by four separate drums. (See Fig. 3.)

The external tubes of the groups I, II, and III are arranged close together to form walls.

In order to provide passages for the heatinggases, the pipes formingthe walls may be bent at the top and bottom. However, inserted walls may also be used and whichare likewise correspondingly broken away.

Fig. l represents the boiler in cross-section and at the same time illustrates the grouping arrangement of two or more drums, while Fig. 2 is a side view of the boiler.

Figs. 3 and e represent modifications of the original forms of construction in so far that in the case of Fig. 3 special drums are arranged instead of the separate chambers formed by partitions in the drums, and in Fig. t the upper drum is divided into three compartments instead of two, while in both serial No. 100,467. (No model.)

cases series ofl tubes forming walls are replaced by inserted walls.

From Fig.` 2 it will be seen that the downpipes are outside the boiler masonry-that is, not within range of the iire and the heatinggases-whereby a downward movement of the water therein is assured.

vThe feed-water enters the lower drum d, Fig. l, and on being heated passes into the upper drum b through `the heating-tubes I. The down-pipe c serves to maintain the circulation of water in the part of the boiler indicated underc I b, so that in case the feed be interrupted there can be no lack of water in the tubes I. As the feed-water introducedinto a is only partially vaporized, it

`collects in b and is conveyed through the down-pipe d into the lower compartment or drum e, whence it rises, passing through the heating-tubes II into the upper part of the boiler and principal steam-chamberf. The down-pipe g is employed for keeping up the circulation in the boiler-compartments e II f. From the pipe g the pipe 71. branches off, through which water is conveyed to the nest of tubes III, which connects the lower drum t' with.wthe upper drum f. The down-pipes g and 72. may be y arranged singly and quite separately-for instance, h may run direct from fto The feed-water, however, may be introduced as required into the upper or lower boiler.

The heating-gases coming from the fire-bars r tirst sweep along the nest of tubes III, then downward over the tubes II and the chamber IVLand downward again over the tubes I, whereupon they enter the flue.

Owing to the circumstance that the warmest heating-gases are brought into contact with the warmest bodies of water and then by stages with the cooler bodies of water and in a direction contrary to that of the ilow of the water an ei'lect approximate to the action of a counter-current is obtained,which in consequence insures the heating-gases being better utilized than isthe case in other tubular boilers.

A further advantage as compared with other systems consists in the small radiating external surfaces of the boilers under the group arrangement, Fig. 1. The upper drum may also be divided into several parts by IOC l partitions, (see Fig. 4,) or instead of a single upper drum several lying separate from one anothermaybeemployed. (SeeFig. 3.) The further construction as regards the downpipes and groups of heating-tubes is the same in this case, the latter being simply adapted to the actual lower or upper drum employed. The effect thereby obtained is precisely the same, and it is of no consequence as regards the value of the invention whether insertionwalls are employed or series of tubes forming walls, as indicated in Figs. l and 2.

The operation of the boiler as in Figs. 3 and 4 is to be seen from the drawings and requires no further explanation.

What I claim, and desire to secure by Letters Patent, is-

1. In a steam-generator, the combination with lower drums or compartments a, e, z', and upper drums or compartments b, f, of a series of heating-tubes I, connecting the compartments a, b, a series of heating-tubes II connecting the compartments e, f, a series of heating-tubes III connecting the compart lnentsf, i; pipes c, d, connecting compartments a, e, with compartment b; pipe g connecting compartments e, f, and pipe h connecting the compartment z' and pipe g, the various series of heating-tubes being so arranged that the series III will be acted upon connecting compartments a, e, with com-v partmentb,l pipe g, connecting compartments e, f, and pipe h connecting the compartment 7l and pipe g, said pipes c, d, g, h, being arranged outside of the masonry, the various series of heating-tubes I, II, III, being so arranged that the series III will be acted upon rst by the heating-gases, and the other series II I in succession thereafter,and said heatinggases being caused to take a direction contrary to that of the water.

In testimony whereof I afX my signature in presence of two witnesses.

ALFRED MEHLHORN. Vtitnesses:

JULIUs RYKE, MARTIN SCHMIETAN. 

